This invention relates to a coating method employing a novel particulate material feed system. The high speed coating process described in for example Nagybaczon et al., U.S. Pat. No. 4,741,918 requires that the particulate material be applied to the substrate in a uniform and controlled manner. Because of the turbulence caused by the high speed of the rotating applicator, it is difficult to apply the particulate material in an efficient and uniform manner. Thus, there is a need, which the present invention addresses, for new coating methods that apply particulate material to the substrate in a uniform and controlled manner.
In addition to the patent disclosed above, the following documents illustrate other known coating methods and apparatus: Lamendola et al., U.S. Pat. No. 5,494,520 and Nagybaczon, U.S. Pat. No. 5,368,890.